The present invention relates to a process for improving properties of a synthetic resin powder, and more particularly to a process for improving properties of a synthetic resin powder which comprises subjecting a latex of a graft-copolymer whose back bone is a rubber to coagulation and adding a silicone oil to the obtained graft-copolymer, thereby obtaining a synthetic resin powder having excellent properties.
Various studies have hitherto been made for improving properties to be required as a powder such as fluidity and blocking resistance of a synthetic resin powder. There are, for instance, a method in which a latex of a copolymer is solidified in a gaseous phase as described in Japanese Unexamined Patent Publication No. 59929/1982, a method in which a latex of a copolymer is spray-dried, a method in which a latex of a copolymer is dispersed in a specific solvent in the state of a sphere and coagulation of the copolymer is carried out, and the like.
However, the known methods have insufficient effects for the improvement of properties of a synthetic resin powder. So, there has not yet been obtained a synthetic resin powder having fluidity and blocking resistance applicable to an automatic weighing of the resin powder and a tendency to grow larger in transport of the resin powder. The present inventors have considered that improvement of the properties of a synthetic resin powder is indispensable for applying to the automatic weighing and the tendency to grow larger in transport.
An object of the present invention is to provide a process for improving properties of a synthetic resin powder, thereby obtaining a resin powder sufficiently applicable to the above-mentioned requirements.
This and other objects of the present invention will become apparant from the following description.